An energy efficient antenna selection for large scale green MIMO systems

This paper proposes an energy efficient antenna selection for large scale (LS) MIMO in green base station (BS). For the maximum energy efficiency (EE) operation of LS-MIMO, antenna selection is necessary, because the RF chains which are connected with antennas are expensive, and consumes a lot of power. However, the excessive amount of antennas in LS-MIMO hinder the efficient antenna selection. We determine optimum antenna number in various circumstances, and show that with LS-MIMO, simple random antenna selection can provide significant EE gain. Moreover, we also show if the EE optimum number of antenna is larger than a certain threshold, the random antenna selection is already very close to the optimum antenna selection. The proposed technique is verified by both mathematical analysis and numerical simulations.